the plugs dont look burned at all they just dont glow . i do have both shims in the head . when i go off the line i see smoke and no bog but when im running full throttle i see very light smoke and the engine stays at about 220 what is the screw on the slide for? i did put a new plug in it today and adjusted it and seems to be running better . im also wondering if that glow plug ignitor on the starter box is just too much for the plug and burning them out today i used a small ignitor and had no problems